Proposition 7.3.4.label Let $X$ be a compact topological space and $E$ be a TVS over $K \in \RC$, then:
- (1)
$C(X; E)$ equipped with the uniform topology is a topological vector space over $K$.
- (2)
If $E$ is locally convex and $\rho: E \to [0, \infty)$ is a continuous seminorm, then
\[[\cdot]_{u, \rho}: C(X; E) \to [0, \infty) \quad f \mapsto \sup_{x \in X}\rho(f(x))\]is a continuous seminorm on $C(X; E)$ with respect to the uniform topology.
The uniform topology on $C(X; E)$ is locally convex, and induced by seminorms of the form $[\cdot]_{u, \rho}$, where $\rho$ ranges over all continuous seminorms on $E$.
- (3)
If $E$ is normed, then
\[[\cdot]_{u}: C(X; E) \quad f \mapsto \sup_{x \in X}\norm{f(x)}_{E}\]is a norm on $C(X; E)$ that induces the uniform topology.
- (4)
If $E$ is complete, then so is $C(X; E)$.
As such, the uniform topology is the canonical topology on $C(X; E)$.
Proof. (1): Since $X$ is compact, for any $f \in C(X; E)$, $f(X) \in \mathfrak{B}(E)$, so (1) holds by Proposition 10.12.1.
(2): By Proposition 11.10.1.
(4): By Proposition 7.3.2.$\square$
Post a Comment